Electric switch



E. F. MEKELBURG J ELECTRIC SWITCH Fild Feb 11, 1927 I INVENTOR.

ATTORNEY April 1, 1930.

Patented Apr. 1, 1930 UNITED STATES PATENT OFFICE 1 EARL IE. MEKELBURG, OF MILWAUKEE, WTSGONSIN, ASSIGNOR TO UNION ELECTRIC MANUFACTURING COMPANY, OF MILWAUKEE, WISCONSIN, A. CORPORATION OF WISCONSIN ELECTRIG SVIITCH Application filed February 11, 1927. Serial No. 167,444.

This invention relates to improvements in electric switches, particularly adapted for drum type switches.

It is one of the objects of the present invention to provide an electric switch which is of very compact form to permit a number of the switches to be closely clamped together on supporting rods. The invention further contemplates the independent removal of said switches, and parts thereof, forrepairs and of Fig. 1.

replacement without disturbing adjacent switches. i

A further object of the invention is to provide an electric switch of the class described in which the constituent parts are constructed almost entirely of stamped or commercial metal to form a switch which is of simple construction, is strong and durable, and which will give a good electrical contact with its cooperative contact members. p

A further object of the invention is to provide an electric switch constructed so as to eliminate any lateral and endwise movements of the contact finger during the operation of the device.

" nected to the end portion of the contact finger.

A further object of the invention is to provide an electric switch ofthe class described which is strong and durable, is efficient inoperation, and is well adaptedfor the purposes described. I

With the above and other objects in view the invention consists of the improved electric switch and its parts and combinations asset w nuts 18 and lock washers 18 one end portlon of a flexible conductor-19 is psitioned,-said forth in the claim, and all equivalents thereof. Iii-the accompanying drawing in .which the same reference numerals indicate the same parts in all of the vlews.

Fig. 1 1s a vertlcal sectional view of the improved electric switch mounted on supports;

' Fig. 4 is a detail perspective view of a lever arm member; and

Flg. 5 1s a sectional view taken on line 5-5 Referring now more particularly to the drawing, it will appear that the numeral '8 indicates a segmental contact mounted on a rotary drum which is positioned to engage the contact end member 9 secured to the outer end portion of a contact finger 10. The rotary drums of drum controllers are usually provided with a plurality of segmental contacts for engagement with fixed contacts. In the present instance a pair of supporting rods 11 form the supports for a plurality of contact fingers 10 and said contact fingers engage their respective drum contacts. Inasmuch as all of the contact fingers are similar, only one I with its coacting segmental contact is shown.

The supporting rods 11 are insulated by tubular members 12 formed of suitable insulating material. To the supporting rods 11 the switch is secured by clamping means comprising a clamping arm 13 having a rightangular extension 13', which extension forms a supporting base platefor the, contact mechanism. Cooperating with the clamping arm 13 is a substantially straight clamping arm 14 formed of suitable metal and firmly heldin clamping engagement with the "supporting rods 11 by means of bolts15 and nuts 16, and interposed between the nuts 16 and the heads of the bolts and the clamping arms 13 and 1%, are split lock washers 17. Surrounding the bolts 15 and between the nuts 16 and outer conductor being formed of a plurality of strips of copper. The other end portion of said conductor is secured to the inner end portion of the contact finger 10. A copper terminal is also clamped between the nuts 16 and 18 and is formed with a tubular end portion 20 for the reception of the end portion of a conduit wire.

The right-angular extension portion 13 of the clamping arm 13 has a'fulcrum strip 21 riveted thereto and said fulcrum strip is formed with offset curved portions 22 and 23 and a forward off-set stop portion 24:. The rear curved portions 22 are of bifurcated or spaced formation, as shown in Fig. 5, and the curved portions 22 and 23 in conjunction with the clamping arm 13 form fulcrum openings or eyes. In the opening formed by the portion 23 the lower portion of a rectangular link 24 is pivotally mounted and a lever arm 25 extending through said link member is provided with transverse rear studs 25' extending through said eyes formed by the curved portions 22, by which means the lever arm is pivotally connected with the clamping arm. The contact finger 10 is mounted on the free end portion of the lever arm 25 and is connected thereto by screws 26 and 27 which also bind the forward end portion of the flexible conductor 19 between the lever arm and the contact finger.

It should be observed that the outer end portion of the lever arm 25 isformed with a pair of downwardly disposed guide lugs 28 adapted to enter recesses 29 formed therefor at each side of the forward end portion of the clamping member 13 and recesses 30 correspondingly formed in the fulcrum strip 21. The lugs, in their engagement with the stock of the clamping and fulcrum members prevent lateral and endwise movement or turning of the contact finger during operation of the device.

The outer end portion of the contact finger 10 is off-set upwardly slightly, as at 10 and secured to the lower face of the off-set portion is the contact end member 9, formed of metal differing in character from that of which the finger is formed, and preferably of copper. The contact end member is formed with a pairof studs 9 which enter apertures 31 therefor in the finger portion 10 and in the assembly of the device the heads of said studs 9 are flattened, as shown. It will thus be seen that the contact end is an independent element and may be removed from the contact finger and replaced if required.

A stop bolt 32 is threaded through a medial portion of the contact finger and is adapted to adjustably bear against the offset portion 24 of the fulcrum strip to limit the inward movement of said finger when disengaged from a contact 8. A spring clip 33 ismounted on the finger and a yielding portion 33 thereof engages the 'headof the ily detachable spring 34 is provided. Said spring is shaped of coiled or bent wire as clearly shown in Figs. 1, 2 and 3, and the base portion 34 of the spring is positioned on the face of the finger against the head of the bolt 27 The rear end of the spring is formed with coils or convolutions 35 and extending from the 'upper portion thereof horizontally forwardly are a pair of arms having hooking portions 36 which engage under the top portion of the link 24:. The tension 7.

of the spring holds the parts, including the spring, in position and the contact end 9 in yielding engagement with the contact segment. If it is desired to replace or repair the finger or contact end, the spring may be disengaged from the link and removed and. the contact finger may then be swung outwardly from the segmental contact to expose the working face of the contact end. Or, if it is desired to replace the finger, it is only necessary to remove the screws 26 and 27. Also, the easy removal of the spring permits it to be readily replaced when necessary.

It is obvious that as the side edge portions of the fingers. extend approximately in straight lines, a plurality of fingers may be positioned in parallel spaced relation quite closely together and any of the fingers may be repaired or replaced without disturbing the others.

As the invention is particularly applicable to drum controllers, the electric switch has been shown as forming part thereof but it is to be understood that the switch may be used for other types of switches.

From the foregoing description it will be seen that the improved electric switch is of very simple and strong construction, and is well adapted for the purposes described.

What I claim as my invention is:

An electric switch, comprising a supporting means having a pair of contacting portions, a right-angular clamping arm engaging said contacting portions and having an outwardly extending tongue at one end thereof, the outer end portion of said tongue being formed with opposed recesses, a cooperating clamping arm also engaging said contacting portions,a fulcrum strip mounted on said right-angular clamping arm and having a stop portion at the outer end thereof, a lever a-rm having one end-portion pivotally carried between said fulcrum strip and saidclamping arm, and provided with downwardly extending guide lugs engaging in said opposed recesses in the outwardlyextending tongue to prevent lateral and endwise movement of the lever arm, an upstanding link clamped between said fulcrum strip and said clamping arm, contact mechanism carried by said lever arm, a spring removably interposed between a portion of the link member and the contact mechanism for yieldingly holding the contact mechanism in an inner position, an independent contact lug carried at the outer end of said contact mechanism, a terminal member, conducting means, one end thereof being connected to said contact mechanism, and a common means for bringing the clamping arms into clamping engagement With the supporting means,

and for securing the terminal member to one end portion of the conducting means.

In testimony whereof, I afiix my signature.

EARL F. MEKELBURG. 

